Visual Basic 6.0

Generating Repeatable Random Data for Testing/Debugging

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Demonstrates how to use the Fortuna PRNG to generate random-looking but repeatable non-random data for the purpose of testing and debugging. Visual Basic 6.0

Dim success As Long
success = 0

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

success = 0

Dim fortuna As New ChilkatPrng

' Normally an application would seed the PRNG with entropy from
' some real random source.  However, sometimes we want the same
' random sequence of bytes for testing and debugging purposes.
' This a reason why GetEntropy and AddEntropy are two different methods.
' An application could omit the call to GetEntropy, and instead pass
' non-random data to AddEntropy. For example:

' Seed the PRNG with non-entropy, so we get a repeatable sequence.
' Note: AddEntropy can be called any number of times.
success = fortuna.AddEntropy("01020304","hex")
success = fortuna.AddEntropy("hello world","ascii")

' Generate some random data:
Dim strRandHex As String
strRandHex = fortuna.GenRandom(16,"hex")
Dim strRandBase64 As String
strRandBase64 = fortuna.GenRandom(22,"base64")
Dim strRandBase58 As String
strRandBase58 = fortuna.GenRandom(32,"base58")

Debug.Print "hex random bytes: " & strRandHex
Debug.Print "base64 random bytes: " & strRandBase64
Debug.Print "base58 random bytes: " & strRandBase58

' Try it again with a different object to verify that the same results are obtained:
Dim fortuna2 As New ChilkatPrng

success = fortuna2.AddEntropy("01020304","hex")
success = fortuna2.AddEntropy("hello world","ascii")

strRandHex = fortuna2.GenRandom(16,"hex")
strRandBase64 = fortuna2.GenRandom(22,"base64")
strRandBase58 = fortuna2.GenRandom(32,"base58")

Debug.Print "hex random bytes: " & strRandHex
Debug.Print "base64 random bytes: " & strRandBase64
Debug.Print "base58 random bytes: " & strRandBase58